There has always been interest in collecting and shooting weapons that have been developed for and used by the military, both handguns and rifles. This interest is held by many civilians, particularly those who served in the military. Because many of the firearms are capable of fully automatic fire, private ownership is both a right and a privilege and is available to qualified, law-abiding individuals who, in accordance with federal law, acquire a Class II or III Firearms Dealer license or those individuals who apply for and obtain the requisite permission from the local authority where they reside and the BATF to become the registered owner of a NFA (National Firearms Act) firearm.
Semi-automatic firearms, on the other hand, are not subject to as rigorous a procedure to own and fire legally and in fact, can currently be legally transferred between individuals. While there is a good selection of handguns and rifles capable of semi-automatic operation, including some "civilian" versions of military firearms, original fully automatic firearms are not readily available in semi-automatic versions. The reasons are numerous including cost of the original firearm, costs to convert it, the necessity for a gunsmith or armorer to perform the work and, the realization on the part of one who has legally acquired such a firearm that the value is often seriously diminished by conversion to semiautomatic operation. Notwithstanding the foregoing reasons, there is a desire for original firearms that have been legally converted to semi-automatic operation and are thus, more readily acquired.
One such firearm is a rifle known as the Browning Automatic Rifle, Caliber 30, Model 1918, which is a gas operated, air cooled automatic arm. Expanding gases from the ignition of powder furnish the energy for the operation or cycling of the rifle. Immediately after firing, as the bullet traverses the barrel and passes an internal gas port prior to exiting from the muzzle, the live gases expand through the gas port into the gas tube or cylinder to impinge against the head of a piston. In so doing, the piston within the gas cylinder is forced rearwardly, toward the buttstock, driving a slide which cycles a combination of internal components while compressing a recoil spring for the return movement.
The slide is configured to pass around the magazine and provides a rear base which engages the hammer. Slots within the receiver are provided to guide reciprocal movement of the slide, rearwardly with the firing of a cartridge and then forwardly to load a subsequent cartridge. The hammer is also pivotally connected to the bolt link, which is, in turn, pivotally connected to the bolt lock. As the slide begins to travel rearwardly, the hammer does so which causes the bolt link to rotate in a clockwise fashion, thereby pulling down on the bolt lock which immediately unlocks the bolt from the receiver. The bolt carries the firing pin, as well as the extractor for removing the empty cartridge from the chamber and the extraction begins concurrently. Once free from the mating receiver surfaces, the bolt now travels rearwardly with the bolt link and hammer as the slide completes its rearward most travel. In so doing, several additional operations continue. The spent cartridge finally clears the chamber and immediately encounters the ejector which applies a lateral force against the head of the cartridge, ejecting it through an opening in the right side of the receiver provided therefor. The slide contacts a buffer in the buttstock, halting its rearward movement, and immediately begins return travel in response to the compression of the recoil spring. Forward movement is now a function of the position of the trigger and the change lever, as will be detailed later.
Assuming the rifle is in the automatic mode and the trigger remains depressed, the continued forward movement of the bolt strips a fresh round from the magazine, eventually chambering it. As the slide moves forward, the bolt link, hammer and bolt lock do likewise until the very last increment of movement. The bolt has just seated the cartridge, which limits its forward movement while the bolt link is caused to rotate counter-clockwise and as it raises within the receiver, thereby lifting the bolt lock into locking engagement within the top of the receiver at which stage, the bolt cannot move rearwardly. At the same instant, the hammer completes it clockwise rotation abruptly, slamming into the head of the firing pin which protrudes from the rear of the bolt. This action causes the firing pin to strike the primer of the chambered cartridge, thereby firing it whereby the sequence is repeated in response to sustained depression of the trigger or until the ammunition becomes exhausted.
Repeat of this cycle is dependent upon the position of the change lever in the automatic position and, the trigger remaining in the fired position. If the operator releases the trigger, the sear is immediately raised into the path of the reciprocating slide. In rearward travel, the slide can push the sear down to pass over it. However, upon the return, the sear is raised by a spring and engages a recess in the underside of the slide which halts its continued forward movement. When this occurs, the action remains opened, and no new round is loaded. Accordingly, the Browning rifle is one which fires from the open bolt and as soon as the trigger is again pulled, the sear is pulled out of the recess, allowing the slide to move forward causing all of the foregoing operations. The bolt closes, taking with it a fresh round from the magazine, which is simultaneously chambered and instantaneously thereafter fired, as the foregoing sequence is allowed to repeat.
If the change lever is positioned for semi-automatic operation, the sear immediately arrests the return movement of the slide after a single cartridge is fired, locking the bolt and action open, with no round chambered. To continue firing, the trigger is first released. When it is subsequently pulled, the sear is removed, the slide proceeds forward and a round is chambered and fired as the hammer finally contacts the head of the firing pin. As should be apparent, while the firearm can be fired in the semi-automatic mode, it is just as readily changed back to automatic operation and hence, all of the ownership restrictions apply.
Basically, the art has not provided a facile means or device by which the Browning Automatic Rifle can be essentially permanently converted to semi-automatic only operation. Accordingly, there is a need for a striking mechanism that is capable of rendering the Browning Automatic Rifle a semi-automatic firearm. Moreover, to comply with the existing federal law such a firearm must meet BATF approval which is given where the Bureau determines that the firearm is not readily converted back to fully automatic operation.